Sluggish moving forward for first 10+ seconds

Greetings all,



My predicament: My manual 2000 Nissan Sentra starts and idles fine. It seems to move in reverse fine (ie, I can shift into reverse, and accelerate in reverse with no loss in power) - however once I try to shift into first gear the engine does not want to cooperate.



It will become extremely sluggish, and will stall if I shift all the way into first (depress the clutch completely) no matter how much gas I’m giving it. I’ll need to nurse the engine for about 10 seconds before the it finally becomes its normal self and full power returns.



This problem has been getting progressively worse (surprise surprise!). Originally it would only be sluggish for about 3 seconds, and then it would instantly kick back to full power. Now it’s feels MUCH longer, and when the engine power does come back it comes back in waves (kind of like it’s working itself back up to it).



This little problem isn’t the end of the world, but it can be pretty obnoxious when I back out in a parking lot, and someone pulls up behind me - or out in traffic from a parallel parking space…



I should also mention that it only happens from a cold start.



Any ideas?



Thanks for your time - and have a great day!



Jon